xref: /openbmc/linux/drivers/thunderbolt/usb4.c (revision c29b9772)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * USB4 specific functionality
4  *
5  * Copyright (C) 2019, Intel Corporation
6  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
7  *	    Rajmohan Mani <rajmohan.mani@intel.com>
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/ktime.h>
12 
13 #include "sb_regs.h"
14 #include "tb.h"
15 
16 #define USB4_DATA_RETRIES		3
17 
18 enum usb4_sb_target {
19 	USB4_SB_TARGET_ROUTER,
20 	USB4_SB_TARGET_PARTNER,
21 	USB4_SB_TARGET_RETIMER,
22 };
23 
24 #define USB4_NVM_READ_OFFSET_MASK	GENMASK(23, 2)
25 #define USB4_NVM_READ_OFFSET_SHIFT	2
26 #define USB4_NVM_READ_LENGTH_MASK	GENMASK(27, 24)
27 #define USB4_NVM_READ_LENGTH_SHIFT	24
28 
29 #define USB4_NVM_SET_OFFSET_MASK	USB4_NVM_READ_OFFSET_MASK
30 #define USB4_NVM_SET_OFFSET_SHIFT	USB4_NVM_READ_OFFSET_SHIFT
31 
32 #define USB4_DROM_ADDRESS_MASK		GENMASK(14, 2)
33 #define USB4_DROM_ADDRESS_SHIFT		2
34 #define USB4_DROM_SIZE_MASK		GENMASK(19, 15)
35 #define USB4_DROM_SIZE_SHIFT		15
36 
37 #define USB4_NVM_SECTOR_SIZE_MASK	GENMASK(23, 0)
38 
39 #define USB4_BA_LENGTH_MASK		GENMASK(7, 0)
40 #define USB4_BA_INDEX_MASK		GENMASK(15, 0)
41 
42 enum usb4_ba_index {
43 	USB4_BA_MAX_USB3 = 0x1,
44 	USB4_BA_MIN_DP_AUX = 0x2,
45 	USB4_BA_MIN_DP_MAIN = 0x3,
46 	USB4_BA_MAX_PCIE = 0x4,
47 	USB4_BA_MAX_HI = 0x5,
48 };
49 
50 #define USB4_BA_VALUE_MASK		GENMASK(31, 16)
51 #define USB4_BA_VALUE_SHIFT		16
52 
53 static int usb4_native_switch_op(struct tb_switch *sw, u16 opcode,
54 				 u32 *metadata, u8 *status,
55 				 const void *tx_data, size_t tx_dwords,
56 				 void *rx_data, size_t rx_dwords)
57 {
58 	u32 val;
59 	int ret;
60 
61 	if (metadata) {
62 		ret = tb_sw_write(sw, metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
63 		if (ret)
64 			return ret;
65 	}
66 	if (tx_dwords) {
67 		ret = tb_sw_write(sw, tx_data, TB_CFG_SWITCH, ROUTER_CS_9,
68 				  tx_dwords);
69 		if (ret)
70 			return ret;
71 	}
72 
73 	val = opcode | ROUTER_CS_26_OV;
74 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
75 	if (ret)
76 		return ret;
77 
78 	ret = tb_switch_wait_for_bit(sw, ROUTER_CS_26, ROUTER_CS_26_OV, 0, 500);
79 	if (ret)
80 		return ret;
81 
82 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
83 	if (ret)
84 		return ret;
85 
86 	if (val & ROUTER_CS_26_ONS)
87 		return -EOPNOTSUPP;
88 
89 	if (status)
90 		*status = (val & ROUTER_CS_26_STATUS_MASK) >>
91 			ROUTER_CS_26_STATUS_SHIFT;
92 
93 	if (metadata) {
94 		ret = tb_sw_read(sw, metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
95 		if (ret)
96 			return ret;
97 	}
98 	if (rx_dwords) {
99 		ret = tb_sw_read(sw, rx_data, TB_CFG_SWITCH, ROUTER_CS_9,
100 				 rx_dwords);
101 		if (ret)
102 			return ret;
103 	}
104 
105 	return 0;
106 }
107 
108 static int __usb4_switch_op(struct tb_switch *sw, u16 opcode, u32 *metadata,
109 			    u8 *status, const void *tx_data, size_t tx_dwords,
110 			    void *rx_data, size_t rx_dwords)
111 {
112 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
113 
114 	if (tx_dwords > NVM_DATA_DWORDS || rx_dwords > NVM_DATA_DWORDS)
115 		return -EINVAL;
116 
117 	/*
118 	 * If the connection manager implementation provides USB4 router
119 	 * operation proxy callback, call it here instead of running the
120 	 * operation natively.
121 	 */
122 	if (cm_ops->usb4_switch_op) {
123 		int ret;
124 
125 		ret = cm_ops->usb4_switch_op(sw, opcode, metadata, status,
126 					     tx_data, tx_dwords, rx_data,
127 					     rx_dwords);
128 		if (ret != -EOPNOTSUPP)
129 			return ret;
130 
131 		/*
132 		 * If the proxy was not supported then run the native
133 		 * router operation instead.
134 		 */
135 	}
136 
137 	return usb4_native_switch_op(sw, opcode, metadata, status, tx_data,
138 				     tx_dwords, rx_data, rx_dwords);
139 }
140 
141 static inline int usb4_switch_op(struct tb_switch *sw, u16 opcode,
142 				 u32 *metadata, u8 *status)
143 {
144 	return __usb4_switch_op(sw, opcode, metadata, status, NULL, 0, NULL, 0);
145 }
146 
147 static inline int usb4_switch_op_data(struct tb_switch *sw, u16 opcode,
148 				      u32 *metadata, u8 *status,
149 				      const void *tx_data, size_t tx_dwords,
150 				      void *rx_data, size_t rx_dwords)
151 {
152 	return __usb4_switch_op(sw, opcode, metadata, status, tx_data,
153 				tx_dwords, rx_data, rx_dwords);
154 }
155 
156 static void usb4_switch_check_wakes(struct tb_switch *sw)
157 {
158 	bool wakeup_usb4 = false;
159 	struct usb4_port *usb4;
160 	struct tb_port *port;
161 	bool wakeup = false;
162 	u32 val;
163 
164 	if (!device_may_wakeup(&sw->dev))
165 		return;
166 
167 	if (tb_route(sw)) {
168 		if (tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_6, 1))
169 			return;
170 
171 		tb_sw_dbg(sw, "PCIe wake: %s, USB3 wake: %s\n",
172 			  (val & ROUTER_CS_6_WOPS) ? "yes" : "no",
173 			  (val & ROUTER_CS_6_WOUS) ? "yes" : "no");
174 
175 		wakeup = val & (ROUTER_CS_6_WOPS | ROUTER_CS_6_WOUS);
176 	}
177 
178 	/*
179 	 * Check for any downstream ports for USB4 wake,
180 	 * connection wake and disconnection wake.
181 	 */
182 	tb_switch_for_each_port(sw, port) {
183 		if (!port->cap_usb4)
184 			continue;
185 
186 		if (tb_port_read(port, &val, TB_CFG_PORT,
187 				 port->cap_usb4 + PORT_CS_18, 1))
188 			break;
189 
190 		tb_port_dbg(port, "USB4 wake: %s, connection wake: %s, disconnection wake: %s\n",
191 			    (val & PORT_CS_18_WOU4S) ? "yes" : "no",
192 			    (val & PORT_CS_18_WOCS) ? "yes" : "no",
193 			    (val & PORT_CS_18_WODS) ? "yes" : "no");
194 
195 		wakeup_usb4 = val & (PORT_CS_18_WOU4S | PORT_CS_18_WOCS |
196 				     PORT_CS_18_WODS);
197 
198 		usb4 = port->usb4;
199 		if (device_may_wakeup(&usb4->dev) && wakeup_usb4)
200 			pm_wakeup_event(&usb4->dev, 0);
201 
202 		wakeup |= wakeup_usb4;
203 	}
204 
205 	if (wakeup)
206 		pm_wakeup_event(&sw->dev, 0);
207 }
208 
209 static bool link_is_usb4(struct tb_port *port)
210 {
211 	u32 val;
212 
213 	if (!port->cap_usb4)
214 		return false;
215 
216 	if (tb_port_read(port, &val, TB_CFG_PORT,
217 			 port->cap_usb4 + PORT_CS_18, 1))
218 		return false;
219 
220 	return !(val & PORT_CS_18_TCM);
221 }
222 
223 /**
224  * usb4_switch_setup() - Additional setup for USB4 device
225  * @sw: USB4 router to setup
226  *
227  * USB4 routers need additional settings in order to enable all the
228  * tunneling. This function enables USB and PCIe tunneling if it can be
229  * enabled (e.g the parent switch also supports them). If USB tunneling
230  * is not available for some reason (like that there is Thunderbolt 3
231  * switch upstream) then the internal xHCI controller is enabled
232  * instead.
233  */
234 int usb4_switch_setup(struct tb_switch *sw)
235 {
236 	struct tb_port *downstream_port;
237 	struct tb_switch *parent;
238 	bool tbt3, xhci;
239 	u32 val = 0;
240 	int ret;
241 
242 	usb4_switch_check_wakes(sw);
243 
244 	if (!tb_route(sw))
245 		return 0;
246 
247 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_6, 1);
248 	if (ret)
249 		return ret;
250 
251 	parent = tb_switch_parent(sw);
252 	downstream_port = tb_port_at(tb_route(sw), parent);
253 	sw->link_usb4 = link_is_usb4(downstream_port);
254 	tb_sw_dbg(sw, "link: %s\n", sw->link_usb4 ? "USB4" : "TBT");
255 
256 	xhci = val & ROUTER_CS_6_HCI;
257 	tbt3 = !(val & ROUTER_CS_6_TNS);
258 
259 	tb_sw_dbg(sw, "TBT3 support: %s, xHCI: %s\n",
260 		  tbt3 ? "yes" : "no", xhci ? "yes" : "no");
261 
262 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
263 	if (ret)
264 		return ret;
265 
266 	if (tb_acpi_may_tunnel_usb3() && sw->link_usb4 &&
267 	    tb_switch_find_port(parent, TB_TYPE_USB3_DOWN)) {
268 		val |= ROUTER_CS_5_UTO;
269 		xhci = false;
270 	}
271 
272 	/*
273 	 * Only enable PCIe tunneling if the parent router supports it
274 	 * and it is not disabled.
275 	 */
276 	if (tb_acpi_may_tunnel_pcie() &&
277 	    tb_switch_find_port(parent, TB_TYPE_PCIE_DOWN)) {
278 		val |= ROUTER_CS_5_PTO;
279 		/*
280 		 * xHCI can be enabled if PCIe tunneling is supported
281 		 * and the parent does not have any USB3 dowstream
282 		 * adapters (so we cannot do USB 3.x tunneling).
283 		 */
284 		if (xhci)
285 			val |= ROUTER_CS_5_HCO;
286 	}
287 
288 	/* TBT3 supported by the CM */
289 	val |= ROUTER_CS_5_C3S;
290 	/* Tunneling configuration is ready now */
291 	val |= ROUTER_CS_5_CV;
292 
293 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
294 	if (ret)
295 		return ret;
296 
297 	return tb_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_CR,
298 				      ROUTER_CS_6_CR, 50);
299 }
300 
301 /**
302  * usb4_switch_read_uid() - Read UID from USB4 router
303  * @sw: USB4 router
304  * @uid: UID is stored here
305  *
306  * Reads 64-bit UID from USB4 router config space.
307  */
308 int usb4_switch_read_uid(struct tb_switch *sw, u64 *uid)
309 {
310 	return tb_sw_read(sw, uid, TB_CFG_SWITCH, ROUTER_CS_7, 2);
311 }
312 
313 static int usb4_switch_drom_read_block(void *data,
314 				       unsigned int dwaddress, void *buf,
315 				       size_t dwords)
316 {
317 	struct tb_switch *sw = data;
318 	u8 status = 0;
319 	u32 metadata;
320 	int ret;
321 
322 	metadata = (dwords << USB4_DROM_SIZE_SHIFT) & USB4_DROM_SIZE_MASK;
323 	metadata |= (dwaddress << USB4_DROM_ADDRESS_SHIFT) &
324 		USB4_DROM_ADDRESS_MASK;
325 
326 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_DROM_READ, &metadata,
327 				  &status, NULL, 0, buf, dwords);
328 	if (ret)
329 		return ret;
330 
331 	return status ? -EIO : 0;
332 }
333 
334 /**
335  * usb4_switch_drom_read() - Read arbitrary bytes from USB4 router DROM
336  * @sw: USB4 router
337  * @address: Byte address inside DROM to start reading
338  * @buf: Buffer where the DROM content is stored
339  * @size: Number of bytes to read from DROM
340  *
341  * Uses USB4 router operations to read router DROM. For devices this
342  * should always work but for hosts it may return %-EOPNOTSUPP in which
343  * case the host router does not have DROM.
344  */
345 int usb4_switch_drom_read(struct tb_switch *sw, unsigned int address, void *buf,
346 			  size_t size)
347 {
348 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
349 				usb4_switch_drom_read_block, sw);
350 }
351 
352 /**
353  * usb4_switch_lane_bonding_possible() - Are conditions met for lane bonding
354  * @sw: USB4 router
355  *
356  * Checks whether conditions are met so that lane bonding can be
357  * established with the upstream router. Call only for device routers.
358  */
359 bool usb4_switch_lane_bonding_possible(struct tb_switch *sw)
360 {
361 	struct tb_port *up;
362 	int ret;
363 	u32 val;
364 
365 	up = tb_upstream_port(sw);
366 	ret = tb_port_read(up, &val, TB_CFG_PORT, up->cap_usb4 + PORT_CS_18, 1);
367 	if (ret)
368 		return false;
369 
370 	return !!(val & PORT_CS_18_BE);
371 }
372 
373 /**
374  * usb4_switch_set_wake() - Enabled/disable wake
375  * @sw: USB4 router
376  * @flags: Wakeup flags (%0 to disable)
377  *
378  * Enables/disables router to wake up from sleep.
379  */
380 int usb4_switch_set_wake(struct tb_switch *sw, unsigned int flags)
381 {
382 	struct usb4_port *usb4;
383 	struct tb_port *port;
384 	u64 route = tb_route(sw);
385 	u32 val;
386 	int ret;
387 
388 	/*
389 	 * Enable wakes coming from all USB4 downstream ports (from
390 	 * child routers). For device routers do this also for the
391 	 * upstream USB4 port.
392 	 */
393 	tb_switch_for_each_port(sw, port) {
394 		if (!tb_port_is_null(port))
395 			continue;
396 		if (!route && tb_is_upstream_port(port))
397 			continue;
398 		if (!port->cap_usb4)
399 			continue;
400 
401 		ret = tb_port_read(port, &val, TB_CFG_PORT,
402 				   port->cap_usb4 + PORT_CS_19, 1);
403 		if (ret)
404 			return ret;
405 
406 		val &= ~(PORT_CS_19_WOC | PORT_CS_19_WOD | PORT_CS_19_WOU4);
407 
408 		if (tb_is_upstream_port(port)) {
409 			val |= PORT_CS_19_WOU4;
410 		} else {
411 			bool configured = val & PORT_CS_19_PC;
412 			usb4 = port->usb4;
413 
414 			if (((flags & TB_WAKE_ON_CONNECT) |
415 			      device_may_wakeup(&usb4->dev)) && !configured)
416 				val |= PORT_CS_19_WOC;
417 			if (((flags & TB_WAKE_ON_DISCONNECT) |
418 			      device_may_wakeup(&usb4->dev)) && configured)
419 				val |= PORT_CS_19_WOD;
420 			if ((flags & TB_WAKE_ON_USB4) && configured)
421 				val |= PORT_CS_19_WOU4;
422 		}
423 
424 		ret = tb_port_write(port, &val, TB_CFG_PORT,
425 				    port->cap_usb4 + PORT_CS_19, 1);
426 		if (ret)
427 			return ret;
428 	}
429 
430 	/*
431 	 * Enable wakes from PCIe, USB 3.x and DP on this router. Only
432 	 * needed for device routers.
433 	 */
434 	if (route) {
435 		ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
436 		if (ret)
437 			return ret;
438 
439 		val &= ~(ROUTER_CS_5_WOP | ROUTER_CS_5_WOU | ROUTER_CS_5_WOD);
440 		if (flags & TB_WAKE_ON_USB3)
441 			val |= ROUTER_CS_5_WOU;
442 		if (flags & TB_WAKE_ON_PCIE)
443 			val |= ROUTER_CS_5_WOP;
444 		if (flags & TB_WAKE_ON_DP)
445 			val |= ROUTER_CS_5_WOD;
446 
447 		ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
448 		if (ret)
449 			return ret;
450 	}
451 
452 	return 0;
453 }
454 
455 /**
456  * usb4_switch_set_sleep() - Prepare the router to enter sleep
457  * @sw: USB4 router
458  *
459  * Sets sleep bit for the router. Returns when the router sleep ready
460  * bit has been asserted.
461  */
462 int usb4_switch_set_sleep(struct tb_switch *sw)
463 {
464 	int ret;
465 	u32 val;
466 
467 	/* Set sleep bit and wait for sleep ready to be asserted */
468 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
469 	if (ret)
470 		return ret;
471 
472 	val |= ROUTER_CS_5_SLP;
473 
474 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
475 	if (ret)
476 		return ret;
477 
478 	return tb_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_SLPR,
479 				      ROUTER_CS_6_SLPR, 500);
480 }
481 
482 /**
483  * usb4_switch_nvm_sector_size() - Return router NVM sector size
484  * @sw: USB4 router
485  *
486  * If the router supports NVM operations this function returns the NVM
487  * sector size in bytes. If NVM operations are not supported returns
488  * %-EOPNOTSUPP.
489  */
490 int usb4_switch_nvm_sector_size(struct tb_switch *sw)
491 {
492 	u32 metadata;
493 	u8 status;
494 	int ret;
495 
496 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SECTOR_SIZE, &metadata,
497 			     &status);
498 	if (ret)
499 		return ret;
500 
501 	if (status)
502 		return status == 0x2 ? -EOPNOTSUPP : -EIO;
503 
504 	return metadata & USB4_NVM_SECTOR_SIZE_MASK;
505 }
506 
507 static int usb4_switch_nvm_read_block(void *data,
508 	unsigned int dwaddress, void *buf, size_t dwords)
509 {
510 	struct tb_switch *sw = data;
511 	u8 status = 0;
512 	u32 metadata;
513 	int ret;
514 
515 	metadata = (dwords << USB4_NVM_READ_LENGTH_SHIFT) &
516 		   USB4_NVM_READ_LENGTH_MASK;
517 	metadata |= (dwaddress << USB4_NVM_READ_OFFSET_SHIFT) &
518 		   USB4_NVM_READ_OFFSET_MASK;
519 
520 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_NVM_READ, &metadata,
521 				  &status, NULL, 0, buf, dwords);
522 	if (ret)
523 		return ret;
524 
525 	return status ? -EIO : 0;
526 }
527 
528 /**
529  * usb4_switch_nvm_read() - Read arbitrary bytes from router NVM
530  * @sw: USB4 router
531  * @address: Starting address in bytes
532  * @buf: Read data is placed here
533  * @size: How many bytes to read
534  *
535  * Reads NVM contents of the router. If NVM is not supported returns
536  * %-EOPNOTSUPP.
537  */
538 int usb4_switch_nvm_read(struct tb_switch *sw, unsigned int address, void *buf,
539 			 size_t size)
540 {
541 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
542 				usb4_switch_nvm_read_block, sw);
543 }
544 
545 /**
546  * usb4_switch_nvm_set_offset() - Set NVM write offset
547  * @sw: USB4 router
548  * @address: Start offset
549  *
550  * Explicitly sets NVM write offset. Normally when writing to NVM this
551  * is done automatically by usb4_switch_nvm_write().
552  *
553  * Returns %0 in success and negative errno if there was a failure.
554  */
555 int usb4_switch_nvm_set_offset(struct tb_switch *sw, unsigned int address)
556 {
557 	u32 metadata, dwaddress;
558 	u8 status = 0;
559 	int ret;
560 
561 	dwaddress = address / 4;
562 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
563 		   USB4_NVM_SET_OFFSET_MASK;
564 
565 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SET_OFFSET, &metadata,
566 			     &status);
567 	if (ret)
568 		return ret;
569 
570 	return status ? -EIO : 0;
571 }
572 
573 static int usb4_switch_nvm_write_next_block(void *data, unsigned int dwaddress,
574 					    const void *buf, size_t dwords)
575 {
576 	struct tb_switch *sw = data;
577 	u8 status;
578 	int ret;
579 
580 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_NVM_WRITE, NULL, &status,
581 				  buf, dwords, NULL, 0);
582 	if (ret)
583 		return ret;
584 
585 	return status ? -EIO : 0;
586 }
587 
588 /**
589  * usb4_switch_nvm_write() - Write to the router NVM
590  * @sw: USB4 router
591  * @address: Start address where to write in bytes
592  * @buf: Pointer to the data to write
593  * @size: Size of @buf in bytes
594  *
595  * Writes @buf to the router NVM using USB4 router operations. If NVM
596  * write is not supported returns %-EOPNOTSUPP.
597  */
598 int usb4_switch_nvm_write(struct tb_switch *sw, unsigned int address,
599 			  const void *buf, size_t size)
600 {
601 	int ret;
602 
603 	ret = usb4_switch_nvm_set_offset(sw, address);
604 	if (ret)
605 		return ret;
606 
607 	return tb_nvm_write_data(address, buf, size, USB4_DATA_RETRIES,
608 				 usb4_switch_nvm_write_next_block, sw);
609 }
610 
611 /**
612  * usb4_switch_nvm_authenticate() - Authenticate new NVM
613  * @sw: USB4 router
614  *
615  * After the new NVM has been written via usb4_switch_nvm_write(), this
616  * function triggers NVM authentication process. The router gets power
617  * cycled and if the authentication is successful the new NVM starts
618  * running. In case of failure returns negative errno.
619  *
620  * The caller should call usb4_switch_nvm_authenticate_status() to read
621  * the status of the authentication after power cycle. It should be the
622  * first router operation to avoid the status being lost.
623  */
624 int usb4_switch_nvm_authenticate(struct tb_switch *sw)
625 {
626 	int ret;
627 
628 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_AUTH, NULL, NULL);
629 	switch (ret) {
630 	/*
631 	 * The router is power cycled once NVM_AUTH is started so it is
632 	 * expected to get any of the following errors back.
633 	 */
634 	case -EACCES:
635 	case -ENOTCONN:
636 	case -ETIMEDOUT:
637 		return 0;
638 
639 	default:
640 		return ret;
641 	}
642 }
643 
644 /**
645  * usb4_switch_nvm_authenticate_status() - Read status of last NVM authenticate
646  * @sw: USB4 router
647  * @status: Status code of the operation
648  *
649  * The function checks if there is status available from the last NVM
650  * authenticate router operation. If there is status then %0 is returned
651  * and the status code is placed in @status. Returns negative errno in case
652  * of failure.
653  *
654  * Must be called before any other router operation.
655  */
656 int usb4_switch_nvm_authenticate_status(struct tb_switch *sw, u32 *status)
657 {
658 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
659 	u16 opcode;
660 	u32 val;
661 	int ret;
662 
663 	if (cm_ops->usb4_switch_nvm_authenticate_status) {
664 		ret = cm_ops->usb4_switch_nvm_authenticate_status(sw, status);
665 		if (ret != -EOPNOTSUPP)
666 			return ret;
667 	}
668 
669 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
670 	if (ret)
671 		return ret;
672 
673 	/* Check that the opcode is correct */
674 	opcode = val & ROUTER_CS_26_OPCODE_MASK;
675 	if (opcode == USB4_SWITCH_OP_NVM_AUTH) {
676 		if (val & ROUTER_CS_26_OV)
677 			return -EBUSY;
678 		if (val & ROUTER_CS_26_ONS)
679 			return -EOPNOTSUPP;
680 
681 		*status = (val & ROUTER_CS_26_STATUS_MASK) >>
682 			ROUTER_CS_26_STATUS_SHIFT;
683 	} else {
684 		*status = 0;
685 	}
686 
687 	return 0;
688 }
689 
690 /**
691  * usb4_switch_credits_init() - Read buffer allocation parameters
692  * @sw: USB4 router
693  *
694  * Reads @sw buffer allocation parameters and initializes @sw buffer
695  * allocation fields accordingly. Specifically @sw->credits_allocation
696  * is set to %true if these parameters can be used in tunneling.
697  *
698  * Returns %0 on success and negative errno otherwise.
699  */
700 int usb4_switch_credits_init(struct tb_switch *sw)
701 {
702 	int max_usb3, min_dp_aux, min_dp_main, max_pcie, max_dma;
703 	int ret, length, i, nports;
704 	const struct tb_port *port;
705 	u32 data[NVM_DATA_DWORDS];
706 	u32 metadata = 0;
707 	u8 status = 0;
708 
709 	memset(data, 0, sizeof(data));
710 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_BUFFER_ALLOC, &metadata,
711 				  &status, NULL, 0, data, ARRAY_SIZE(data));
712 	if (ret)
713 		return ret;
714 	if (status)
715 		return -EIO;
716 
717 	length = metadata & USB4_BA_LENGTH_MASK;
718 	if (WARN_ON(length > ARRAY_SIZE(data)))
719 		return -EMSGSIZE;
720 
721 	max_usb3 = -1;
722 	min_dp_aux = -1;
723 	min_dp_main = -1;
724 	max_pcie = -1;
725 	max_dma = -1;
726 
727 	tb_sw_dbg(sw, "credit allocation parameters:\n");
728 
729 	for (i = 0; i < length; i++) {
730 		u16 index, value;
731 
732 		index = data[i] & USB4_BA_INDEX_MASK;
733 		value = (data[i] & USB4_BA_VALUE_MASK) >> USB4_BA_VALUE_SHIFT;
734 
735 		switch (index) {
736 		case USB4_BA_MAX_USB3:
737 			tb_sw_dbg(sw, " USB3: %u\n", value);
738 			max_usb3 = value;
739 			break;
740 		case USB4_BA_MIN_DP_AUX:
741 			tb_sw_dbg(sw, " DP AUX: %u\n", value);
742 			min_dp_aux = value;
743 			break;
744 		case USB4_BA_MIN_DP_MAIN:
745 			tb_sw_dbg(sw, " DP main: %u\n", value);
746 			min_dp_main = value;
747 			break;
748 		case USB4_BA_MAX_PCIE:
749 			tb_sw_dbg(sw, " PCIe: %u\n", value);
750 			max_pcie = value;
751 			break;
752 		case USB4_BA_MAX_HI:
753 			tb_sw_dbg(sw, " DMA: %u\n", value);
754 			max_dma = value;
755 			break;
756 		default:
757 			tb_sw_dbg(sw, " unknown credit allocation index %#x, skipping\n",
758 				  index);
759 			break;
760 		}
761 	}
762 
763 	/*
764 	 * Validate the buffer allocation preferences. If we find
765 	 * issues, log a warning and fall back using the hard-coded
766 	 * values.
767 	 */
768 
769 	/* Host router must report baMaxHI */
770 	if (!tb_route(sw) && max_dma < 0) {
771 		tb_sw_warn(sw, "host router is missing baMaxHI\n");
772 		goto err_invalid;
773 	}
774 
775 	nports = 0;
776 	tb_switch_for_each_port(sw, port) {
777 		if (tb_port_is_null(port))
778 			nports++;
779 	}
780 
781 	/* Must have DP buffer allocation (multiple USB4 ports) */
782 	if (nports > 2 && (min_dp_aux < 0 || min_dp_main < 0)) {
783 		tb_sw_warn(sw, "multiple USB4 ports require baMinDPaux/baMinDPmain\n");
784 		goto err_invalid;
785 	}
786 
787 	tb_switch_for_each_port(sw, port) {
788 		if (tb_port_is_dpout(port) && min_dp_main < 0) {
789 			tb_sw_warn(sw, "missing baMinDPmain");
790 			goto err_invalid;
791 		}
792 		if ((tb_port_is_dpin(port) || tb_port_is_dpout(port)) &&
793 		    min_dp_aux < 0) {
794 			tb_sw_warn(sw, "missing baMinDPaux");
795 			goto err_invalid;
796 		}
797 		if ((tb_port_is_usb3_down(port) || tb_port_is_usb3_up(port)) &&
798 		    max_usb3 < 0) {
799 			tb_sw_warn(sw, "missing baMaxUSB3");
800 			goto err_invalid;
801 		}
802 		if ((tb_port_is_pcie_down(port) || tb_port_is_pcie_up(port)) &&
803 		    max_pcie < 0) {
804 			tb_sw_warn(sw, "missing baMaxPCIe");
805 			goto err_invalid;
806 		}
807 	}
808 
809 	/*
810 	 * Buffer allocation passed the validation so we can use it in
811 	 * path creation.
812 	 */
813 	sw->credit_allocation = true;
814 	if (max_usb3 > 0)
815 		sw->max_usb3_credits = max_usb3;
816 	if (min_dp_aux > 0)
817 		sw->min_dp_aux_credits = min_dp_aux;
818 	if (min_dp_main > 0)
819 		sw->min_dp_main_credits = min_dp_main;
820 	if (max_pcie > 0)
821 		sw->max_pcie_credits = max_pcie;
822 	if (max_dma > 0)
823 		sw->max_dma_credits = max_dma;
824 
825 	return 0;
826 
827 err_invalid:
828 	return -EINVAL;
829 }
830 
831 /**
832  * usb4_switch_query_dp_resource() - Query availability of DP IN resource
833  * @sw: USB4 router
834  * @in: DP IN adapter
835  *
836  * For DP tunneling this function can be used to query availability of
837  * DP IN resource. Returns true if the resource is available for DP
838  * tunneling, false otherwise.
839  */
840 bool usb4_switch_query_dp_resource(struct tb_switch *sw, struct tb_port *in)
841 {
842 	u32 metadata = in->port;
843 	u8 status;
844 	int ret;
845 
846 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_QUERY_DP_RESOURCE, &metadata,
847 			     &status);
848 	/*
849 	 * If DP resource allocation is not supported assume it is
850 	 * always available.
851 	 */
852 	if (ret == -EOPNOTSUPP)
853 		return true;
854 	else if (ret)
855 		return false;
856 
857 	return !status;
858 }
859 
860 /**
861  * usb4_switch_alloc_dp_resource() - Allocate DP IN resource
862  * @sw: USB4 router
863  * @in: DP IN adapter
864  *
865  * Allocates DP IN resource for DP tunneling using USB4 router
866  * operations. If the resource was allocated returns %0. Otherwise
867  * returns negative errno, in particular %-EBUSY if the resource is
868  * already allocated.
869  */
870 int usb4_switch_alloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
871 {
872 	u32 metadata = in->port;
873 	u8 status;
874 	int ret;
875 
876 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_ALLOC_DP_RESOURCE, &metadata,
877 			     &status);
878 	if (ret == -EOPNOTSUPP)
879 		return 0;
880 	else if (ret)
881 		return ret;
882 
883 	return status ? -EBUSY : 0;
884 }
885 
886 /**
887  * usb4_switch_dealloc_dp_resource() - Releases allocated DP IN resource
888  * @sw: USB4 router
889  * @in: DP IN adapter
890  *
891  * Releases the previously allocated DP IN resource.
892  */
893 int usb4_switch_dealloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
894 {
895 	u32 metadata = in->port;
896 	u8 status;
897 	int ret;
898 
899 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_DEALLOC_DP_RESOURCE, &metadata,
900 			     &status);
901 	if (ret == -EOPNOTSUPP)
902 		return 0;
903 	else if (ret)
904 		return ret;
905 
906 	return status ? -EIO : 0;
907 }
908 
909 static int usb4_port_idx(const struct tb_switch *sw, const struct tb_port *port)
910 {
911 	struct tb_port *p;
912 	int usb4_idx = 0;
913 
914 	/* Assume port is primary */
915 	tb_switch_for_each_port(sw, p) {
916 		if (!tb_port_is_null(p))
917 			continue;
918 		if (tb_is_upstream_port(p))
919 			continue;
920 		if (!p->link_nr) {
921 			if (p == port)
922 				break;
923 			usb4_idx++;
924 		}
925 	}
926 
927 	return usb4_idx;
928 }
929 
930 /**
931  * usb4_switch_map_pcie_down() - Map USB4 port to a PCIe downstream adapter
932  * @sw: USB4 router
933  * @port: USB4 port
934  *
935  * USB4 routers have direct mapping between USB4 ports and PCIe
936  * downstream adapters where the PCIe topology is extended. This
937  * function returns the corresponding downstream PCIe adapter or %NULL
938  * if no such mapping was possible.
939  */
940 struct tb_port *usb4_switch_map_pcie_down(struct tb_switch *sw,
941 					  const struct tb_port *port)
942 {
943 	int usb4_idx = usb4_port_idx(sw, port);
944 	struct tb_port *p;
945 	int pcie_idx = 0;
946 
947 	/* Find PCIe down port matching usb4_port */
948 	tb_switch_for_each_port(sw, p) {
949 		if (!tb_port_is_pcie_down(p))
950 			continue;
951 
952 		if (pcie_idx == usb4_idx)
953 			return p;
954 
955 		pcie_idx++;
956 	}
957 
958 	return NULL;
959 }
960 
961 /**
962  * usb4_switch_map_usb3_down() - Map USB4 port to a USB3 downstream adapter
963  * @sw: USB4 router
964  * @port: USB4 port
965  *
966  * USB4 routers have direct mapping between USB4 ports and USB 3.x
967  * downstream adapters where the USB 3.x topology is extended. This
968  * function returns the corresponding downstream USB 3.x adapter or
969  * %NULL if no such mapping was possible.
970  */
971 struct tb_port *usb4_switch_map_usb3_down(struct tb_switch *sw,
972 					  const struct tb_port *port)
973 {
974 	int usb4_idx = usb4_port_idx(sw, port);
975 	struct tb_port *p;
976 	int usb_idx = 0;
977 
978 	/* Find USB3 down port matching usb4_port */
979 	tb_switch_for_each_port(sw, p) {
980 		if (!tb_port_is_usb3_down(p))
981 			continue;
982 
983 		if (usb_idx == usb4_idx)
984 			return p;
985 
986 		usb_idx++;
987 	}
988 
989 	return NULL;
990 }
991 
992 /**
993  * usb4_switch_add_ports() - Add USB4 ports for this router
994  * @sw: USB4 router
995  *
996  * For USB4 router finds all USB4 ports and registers devices for each.
997  * Can be called to any router.
998  *
999  * Return %0 in case of success and negative errno in case of failure.
1000  */
1001 int usb4_switch_add_ports(struct tb_switch *sw)
1002 {
1003 	struct tb_port *port;
1004 
1005 	if (tb_switch_is_icm(sw) || !tb_switch_is_usb4(sw))
1006 		return 0;
1007 
1008 	tb_switch_for_each_port(sw, port) {
1009 		struct usb4_port *usb4;
1010 
1011 		if (!tb_port_is_null(port))
1012 			continue;
1013 		if (!port->cap_usb4)
1014 			continue;
1015 
1016 		usb4 = usb4_port_device_add(port);
1017 		if (IS_ERR(usb4)) {
1018 			usb4_switch_remove_ports(sw);
1019 			return PTR_ERR(usb4);
1020 		}
1021 
1022 		port->usb4 = usb4;
1023 	}
1024 
1025 	return 0;
1026 }
1027 
1028 /**
1029  * usb4_switch_remove_ports() - Removes USB4 ports from this router
1030  * @sw: USB4 router
1031  *
1032  * Unregisters previously registered USB4 ports.
1033  */
1034 void usb4_switch_remove_ports(struct tb_switch *sw)
1035 {
1036 	struct tb_port *port;
1037 
1038 	tb_switch_for_each_port(sw, port) {
1039 		if (port->usb4) {
1040 			usb4_port_device_remove(port->usb4);
1041 			port->usb4 = NULL;
1042 		}
1043 	}
1044 }
1045 
1046 /**
1047  * usb4_port_unlock() - Unlock USB4 downstream port
1048  * @port: USB4 port to unlock
1049  *
1050  * Unlocks USB4 downstream port so that the connection manager can
1051  * access the router below this port.
1052  */
1053 int usb4_port_unlock(struct tb_port *port)
1054 {
1055 	int ret;
1056 	u32 val;
1057 
1058 	ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
1059 	if (ret)
1060 		return ret;
1061 
1062 	val &= ~ADP_CS_4_LCK;
1063 	return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
1064 }
1065 
1066 /**
1067  * usb4_port_hotplug_enable() - Enables hotplug for a port
1068  * @port: USB4 port to operate on
1069  *
1070  * Enables hot plug events on a given port. This is only intended
1071  * to be used on lane, DP-IN, and DP-OUT adapters.
1072  */
1073 int usb4_port_hotplug_enable(struct tb_port *port)
1074 {
1075 	int ret;
1076 	u32 val;
1077 
1078 	ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_5, 1);
1079 	if (ret)
1080 		return ret;
1081 
1082 	val &= ~ADP_CS_5_DHP;
1083 	return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_5, 1);
1084 }
1085 
1086 static int usb4_port_set_configured(struct tb_port *port, bool configured)
1087 {
1088 	int ret;
1089 	u32 val;
1090 
1091 	if (!port->cap_usb4)
1092 		return -EINVAL;
1093 
1094 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1095 			   port->cap_usb4 + PORT_CS_19, 1);
1096 	if (ret)
1097 		return ret;
1098 
1099 	if (configured)
1100 		val |= PORT_CS_19_PC;
1101 	else
1102 		val &= ~PORT_CS_19_PC;
1103 
1104 	return tb_port_write(port, &val, TB_CFG_PORT,
1105 			     port->cap_usb4 + PORT_CS_19, 1);
1106 }
1107 
1108 /**
1109  * usb4_port_configure() - Set USB4 port configured
1110  * @port: USB4 router
1111  *
1112  * Sets the USB4 link to be configured for power management purposes.
1113  */
1114 int usb4_port_configure(struct tb_port *port)
1115 {
1116 	return usb4_port_set_configured(port, true);
1117 }
1118 
1119 /**
1120  * usb4_port_unconfigure() - Set USB4 port unconfigured
1121  * @port: USB4 router
1122  *
1123  * Sets the USB4 link to be unconfigured for power management purposes.
1124  */
1125 void usb4_port_unconfigure(struct tb_port *port)
1126 {
1127 	usb4_port_set_configured(port, false);
1128 }
1129 
1130 static int usb4_set_xdomain_configured(struct tb_port *port, bool configured)
1131 {
1132 	int ret;
1133 	u32 val;
1134 
1135 	if (!port->cap_usb4)
1136 		return -EINVAL;
1137 
1138 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1139 			   port->cap_usb4 + PORT_CS_19, 1);
1140 	if (ret)
1141 		return ret;
1142 
1143 	if (configured)
1144 		val |= PORT_CS_19_PID;
1145 	else
1146 		val &= ~PORT_CS_19_PID;
1147 
1148 	return tb_port_write(port, &val, TB_CFG_PORT,
1149 			     port->cap_usb4 + PORT_CS_19, 1);
1150 }
1151 
1152 /**
1153  * usb4_port_configure_xdomain() - Configure port for XDomain
1154  * @port: USB4 port connected to another host
1155  * @xd: XDomain that is connected to the port
1156  *
1157  * Marks the USB4 port as being connected to another host and updates
1158  * the link type. Returns %0 in success and negative errno in failure.
1159  */
1160 int usb4_port_configure_xdomain(struct tb_port *port, struct tb_xdomain *xd)
1161 {
1162 	xd->link_usb4 = link_is_usb4(port);
1163 	return usb4_set_xdomain_configured(port, true);
1164 }
1165 
1166 /**
1167  * usb4_port_unconfigure_xdomain() - Unconfigure port for XDomain
1168  * @port: USB4 port that was connected to another host
1169  *
1170  * Clears USB4 port from being marked as XDomain.
1171  */
1172 void usb4_port_unconfigure_xdomain(struct tb_port *port)
1173 {
1174 	usb4_set_xdomain_configured(port, false);
1175 }
1176 
1177 static int usb4_port_wait_for_bit(struct tb_port *port, u32 offset, u32 bit,
1178 				  u32 value, int timeout_msec)
1179 {
1180 	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
1181 
1182 	do {
1183 		u32 val;
1184 		int ret;
1185 
1186 		ret = tb_port_read(port, &val, TB_CFG_PORT, offset, 1);
1187 		if (ret)
1188 			return ret;
1189 
1190 		if ((val & bit) == value)
1191 			return 0;
1192 
1193 		usleep_range(50, 100);
1194 	} while (ktime_before(ktime_get(), timeout));
1195 
1196 	return -ETIMEDOUT;
1197 }
1198 
1199 static int usb4_port_read_data(struct tb_port *port, void *data, size_t dwords)
1200 {
1201 	if (dwords > NVM_DATA_DWORDS)
1202 		return -EINVAL;
1203 
1204 	return tb_port_read(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
1205 			    dwords);
1206 }
1207 
1208 static int usb4_port_write_data(struct tb_port *port, const void *data,
1209 				size_t dwords)
1210 {
1211 	if (dwords > NVM_DATA_DWORDS)
1212 		return -EINVAL;
1213 
1214 	return tb_port_write(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
1215 			     dwords);
1216 }
1217 
1218 static int usb4_port_sb_read(struct tb_port *port, enum usb4_sb_target target,
1219 			     u8 index, u8 reg, void *buf, u8 size)
1220 {
1221 	size_t dwords = DIV_ROUND_UP(size, 4);
1222 	int ret;
1223 	u32 val;
1224 
1225 	if (!port->cap_usb4)
1226 		return -EINVAL;
1227 
1228 	val = reg;
1229 	val |= size << PORT_CS_1_LENGTH_SHIFT;
1230 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
1231 	if (target == USB4_SB_TARGET_RETIMER)
1232 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
1233 	val |= PORT_CS_1_PND;
1234 
1235 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1236 			    port->cap_usb4 + PORT_CS_1, 1);
1237 	if (ret)
1238 		return ret;
1239 
1240 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
1241 				     PORT_CS_1_PND, 0, 500);
1242 	if (ret)
1243 		return ret;
1244 
1245 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1246 			    port->cap_usb4 + PORT_CS_1, 1);
1247 	if (ret)
1248 		return ret;
1249 
1250 	if (val & PORT_CS_1_NR)
1251 		return -ENODEV;
1252 	if (val & PORT_CS_1_RC)
1253 		return -EIO;
1254 
1255 	return buf ? usb4_port_read_data(port, buf, dwords) : 0;
1256 }
1257 
1258 static int usb4_port_sb_write(struct tb_port *port, enum usb4_sb_target target,
1259 			      u8 index, u8 reg, const void *buf, u8 size)
1260 {
1261 	size_t dwords = DIV_ROUND_UP(size, 4);
1262 	int ret;
1263 	u32 val;
1264 
1265 	if (!port->cap_usb4)
1266 		return -EINVAL;
1267 
1268 	if (buf) {
1269 		ret = usb4_port_write_data(port, buf, dwords);
1270 		if (ret)
1271 			return ret;
1272 	}
1273 
1274 	val = reg;
1275 	val |= size << PORT_CS_1_LENGTH_SHIFT;
1276 	val |= PORT_CS_1_WNR_WRITE;
1277 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
1278 	if (target == USB4_SB_TARGET_RETIMER)
1279 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
1280 	val |= PORT_CS_1_PND;
1281 
1282 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1283 			    port->cap_usb4 + PORT_CS_1, 1);
1284 	if (ret)
1285 		return ret;
1286 
1287 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
1288 				     PORT_CS_1_PND, 0, 500);
1289 	if (ret)
1290 		return ret;
1291 
1292 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1293 			    port->cap_usb4 + PORT_CS_1, 1);
1294 	if (ret)
1295 		return ret;
1296 
1297 	if (val & PORT_CS_1_NR)
1298 		return -ENODEV;
1299 	if (val & PORT_CS_1_RC)
1300 		return -EIO;
1301 
1302 	return 0;
1303 }
1304 
1305 static int usb4_port_sb_op(struct tb_port *port, enum usb4_sb_target target,
1306 			   u8 index, enum usb4_sb_opcode opcode, int timeout_msec)
1307 {
1308 	ktime_t timeout;
1309 	u32 val;
1310 	int ret;
1311 
1312 	val = opcode;
1313 	ret = usb4_port_sb_write(port, target, index, USB4_SB_OPCODE, &val,
1314 				 sizeof(val));
1315 	if (ret)
1316 		return ret;
1317 
1318 	timeout = ktime_add_ms(ktime_get(), timeout_msec);
1319 
1320 	do {
1321 		/* Check results */
1322 		ret = usb4_port_sb_read(port, target, index, USB4_SB_OPCODE,
1323 					&val, sizeof(val));
1324 		if (ret)
1325 			return ret;
1326 
1327 		switch (val) {
1328 		case 0:
1329 			return 0;
1330 
1331 		case USB4_SB_OPCODE_ERR:
1332 			return -EAGAIN;
1333 
1334 		case USB4_SB_OPCODE_ONS:
1335 			return -EOPNOTSUPP;
1336 
1337 		default:
1338 			if (val != opcode)
1339 				return -EIO;
1340 			break;
1341 		}
1342 	} while (ktime_before(ktime_get(), timeout));
1343 
1344 	return -ETIMEDOUT;
1345 }
1346 
1347 static int usb4_port_set_router_offline(struct tb_port *port, bool offline)
1348 {
1349 	u32 val = !offline;
1350 	int ret;
1351 
1352 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1353 				  USB4_SB_METADATA, &val, sizeof(val));
1354 	if (ret)
1355 		return ret;
1356 
1357 	val = USB4_SB_OPCODE_ROUTER_OFFLINE;
1358 	return usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1359 				  USB4_SB_OPCODE, &val, sizeof(val));
1360 }
1361 
1362 /**
1363  * usb4_port_router_offline() - Put the USB4 port to offline mode
1364  * @port: USB4 port
1365  *
1366  * This function puts the USB4 port into offline mode. In this mode the
1367  * port does not react on hotplug events anymore. This needs to be
1368  * called before retimer access is done when the USB4 links is not up.
1369  *
1370  * Returns %0 in case of success and negative errno if there was an
1371  * error.
1372  */
1373 int usb4_port_router_offline(struct tb_port *port)
1374 {
1375 	return usb4_port_set_router_offline(port, true);
1376 }
1377 
1378 /**
1379  * usb4_port_router_online() - Put the USB4 port back to online
1380  * @port: USB4 port
1381  *
1382  * Makes the USB4 port functional again.
1383  */
1384 int usb4_port_router_online(struct tb_port *port)
1385 {
1386 	return usb4_port_set_router_offline(port, false);
1387 }
1388 
1389 /**
1390  * usb4_port_enumerate_retimers() - Send RT broadcast transaction
1391  * @port: USB4 port
1392  *
1393  * This forces the USB4 port to send broadcast RT transaction which
1394  * makes the retimers on the link to assign index to themselves. Returns
1395  * %0 in case of success and negative errno if there was an error.
1396  */
1397 int usb4_port_enumerate_retimers(struct tb_port *port)
1398 {
1399 	u32 val;
1400 
1401 	val = USB4_SB_OPCODE_ENUMERATE_RETIMERS;
1402 	return usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1403 				  USB4_SB_OPCODE, &val, sizeof(val));
1404 }
1405 
1406 /**
1407  * usb4_port_clx_supported() - Check if CLx is supported by the link
1408  * @port: Port to check for CLx support for
1409  *
1410  * PORT_CS_18_CPS bit reflects if the link supports CLx including
1411  * active cables (if connected on the link).
1412  */
1413 bool usb4_port_clx_supported(struct tb_port *port)
1414 {
1415 	int ret;
1416 	u32 val;
1417 
1418 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1419 			   port->cap_usb4 + PORT_CS_18, 1);
1420 	if (ret)
1421 		return false;
1422 
1423 	return !!(val & PORT_CS_18_CPS);
1424 }
1425 
1426 /**
1427  * usb4_port_margining_caps() - Read USB4 port marginig capabilities
1428  * @port: USB4 port
1429  * @caps: Array with at least two elements to hold the results
1430  *
1431  * Reads the USB4 port lane margining capabilities into @caps.
1432  */
1433 int usb4_port_margining_caps(struct tb_port *port, u32 *caps)
1434 {
1435 	int ret;
1436 
1437 	ret = usb4_port_sb_op(port, USB4_SB_TARGET_ROUTER, 0,
1438 			      USB4_SB_OPCODE_READ_LANE_MARGINING_CAP, 500);
1439 	if (ret)
1440 		return ret;
1441 
1442 	return usb4_port_sb_read(port, USB4_SB_TARGET_ROUTER, 0,
1443 				 USB4_SB_DATA, caps, sizeof(*caps) * 2);
1444 }
1445 
1446 /**
1447  * usb4_port_hw_margin() - Run hardware lane margining on port
1448  * @port: USB4 port
1449  * @lanes: Which lanes to run (must match the port capabilities). Can be
1450  *	   %0, %1 or %7.
1451  * @ber_level: BER level contour value
1452  * @timing: Perform timing margining instead of voltage
1453  * @right_high: Use Right/high margin instead of left/low
1454  * @results: Array with at least two elements to hold the results
1455  *
1456  * Runs hardware lane margining on USB4 port and returns the result in
1457  * @results.
1458  */
1459 int usb4_port_hw_margin(struct tb_port *port, unsigned int lanes,
1460 			unsigned int ber_level, bool timing, bool right_high,
1461 			u32 *results)
1462 {
1463 	u32 val;
1464 	int ret;
1465 
1466 	val = lanes;
1467 	if (timing)
1468 		val |= USB4_MARGIN_HW_TIME;
1469 	if (right_high)
1470 		val |= USB4_MARGIN_HW_RH;
1471 	if (ber_level)
1472 		val |= (ber_level << USB4_MARGIN_HW_BER_SHIFT) &
1473 			USB4_MARGIN_HW_BER_MASK;
1474 
1475 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1476 				 USB4_SB_METADATA, &val, sizeof(val));
1477 	if (ret)
1478 		return ret;
1479 
1480 	ret = usb4_port_sb_op(port, USB4_SB_TARGET_ROUTER, 0,
1481 			      USB4_SB_OPCODE_RUN_HW_LANE_MARGINING, 2500);
1482 	if (ret)
1483 		return ret;
1484 
1485 	return usb4_port_sb_read(port, USB4_SB_TARGET_ROUTER, 0,
1486 				 USB4_SB_DATA, results, sizeof(*results) * 2);
1487 }
1488 
1489 /**
1490  * usb4_port_sw_margin() - Run software lane margining on port
1491  * @port: USB4 port
1492  * @lanes: Which lanes to run (must match the port capabilities). Can be
1493  *	   %0, %1 or %7.
1494  * @timing: Perform timing margining instead of voltage
1495  * @right_high: Use Right/high margin instead of left/low
1496  * @counter: What to do with the error counter
1497  *
1498  * Runs software lane margining on USB4 port. Read back the error
1499  * counters by calling usb4_port_sw_margin_errors(). Returns %0 in
1500  * success and negative errno otherwise.
1501  */
1502 int usb4_port_sw_margin(struct tb_port *port, unsigned int lanes, bool timing,
1503 			bool right_high, u32 counter)
1504 {
1505 	u32 val;
1506 	int ret;
1507 
1508 	val = lanes;
1509 	if (timing)
1510 		val |= USB4_MARGIN_SW_TIME;
1511 	if (right_high)
1512 		val |= USB4_MARGIN_SW_RH;
1513 	val |= (counter << USB4_MARGIN_SW_COUNTER_SHIFT) &
1514 		USB4_MARGIN_SW_COUNTER_MASK;
1515 
1516 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1517 				 USB4_SB_METADATA, &val, sizeof(val));
1518 	if (ret)
1519 		return ret;
1520 
1521 	return usb4_port_sb_op(port, USB4_SB_TARGET_ROUTER, 0,
1522 			       USB4_SB_OPCODE_RUN_SW_LANE_MARGINING, 2500);
1523 }
1524 
1525 /**
1526  * usb4_port_sw_margin_errors() - Read the software margining error counters
1527  * @port: USB4 port
1528  * @errors: Error metadata is copied here.
1529  *
1530  * This reads back the software margining error counters from the port.
1531  * Returns %0 in success and negative errno otherwise.
1532  */
1533 int usb4_port_sw_margin_errors(struct tb_port *port, u32 *errors)
1534 {
1535 	int ret;
1536 
1537 	ret = usb4_port_sb_op(port, USB4_SB_TARGET_ROUTER, 0,
1538 			      USB4_SB_OPCODE_READ_SW_MARGIN_ERR, 150);
1539 	if (ret)
1540 		return ret;
1541 
1542 	return usb4_port_sb_read(port, USB4_SB_TARGET_ROUTER, 0,
1543 				 USB4_SB_METADATA, errors, sizeof(*errors));
1544 }
1545 
1546 static inline int usb4_port_retimer_op(struct tb_port *port, u8 index,
1547 				       enum usb4_sb_opcode opcode,
1548 				       int timeout_msec)
1549 {
1550 	return usb4_port_sb_op(port, USB4_SB_TARGET_RETIMER, index, opcode,
1551 			       timeout_msec);
1552 }
1553 
1554 /**
1555  * usb4_port_retimer_set_inbound_sbtx() - Enable sideband channel transactions
1556  * @port: USB4 port
1557  * @index: Retimer index
1558  *
1559  * Enables sideband channel transations on SBTX. Can be used when USB4
1560  * link does not go up, for example if there is no device connected.
1561  */
1562 int usb4_port_retimer_set_inbound_sbtx(struct tb_port *port, u8 index)
1563 {
1564 	int ret;
1565 
1566 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_SET_INBOUND_SBTX,
1567 				   500);
1568 
1569 	if (ret != -ENODEV)
1570 		return ret;
1571 
1572 	/*
1573 	 * Per the USB4 retimer spec, the retimer is not required to
1574 	 * send an RT (Retimer Transaction) response for the first
1575 	 * SET_INBOUND_SBTX command
1576 	 */
1577 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_SET_INBOUND_SBTX,
1578 				    500);
1579 }
1580 
1581 /**
1582  * usb4_port_retimer_read() - Read from retimer sideband registers
1583  * @port: USB4 port
1584  * @index: Retimer index
1585  * @reg: Sideband register to read
1586  * @buf: Data from @reg is stored here
1587  * @size: Number of bytes to read
1588  *
1589  * Function reads retimer sideband registers starting from @reg. The
1590  * retimer is connected to @port at @index. Returns %0 in case of
1591  * success, and read data is copied to @buf. If there is no retimer
1592  * present at given @index returns %-ENODEV. In any other failure
1593  * returns negative errno.
1594  */
1595 int usb4_port_retimer_read(struct tb_port *port, u8 index, u8 reg, void *buf,
1596 			   u8 size)
1597 {
1598 	return usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index, reg, buf,
1599 				 size);
1600 }
1601 
1602 /**
1603  * usb4_port_retimer_write() - Write to retimer sideband registers
1604  * @port: USB4 port
1605  * @index: Retimer index
1606  * @reg: Sideband register to write
1607  * @buf: Data that is written starting from @reg
1608  * @size: Number of bytes to write
1609  *
1610  * Writes retimer sideband registers starting from @reg. The retimer is
1611  * connected to @port at @index. Returns %0 in case of success. If there
1612  * is no retimer present at given @index returns %-ENODEV. In any other
1613  * failure returns negative errno.
1614  */
1615 int usb4_port_retimer_write(struct tb_port *port, u8 index, u8 reg,
1616 			    const void *buf, u8 size)
1617 {
1618 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index, reg, buf,
1619 				  size);
1620 }
1621 
1622 /**
1623  * usb4_port_retimer_is_last() - Is the retimer last on-board retimer
1624  * @port: USB4 port
1625  * @index: Retimer index
1626  *
1627  * If the retimer at @index is last one (connected directly to the
1628  * Type-C port) this function returns %1. If it is not returns %0. If
1629  * the retimer is not present returns %-ENODEV. Otherwise returns
1630  * negative errno.
1631  */
1632 int usb4_port_retimer_is_last(struct tb_port *port, u8 index)
1633 {
1634 	u32 metadata;
1635 	int ret;
1636 
1637 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_QUERY_LAST_RETIMER,
1638 				   500);
1639 	if (ret)
1640 		return ret;
1641 
1642 	ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA, &metadata,
1643 				     sizeof(metadata));
1644 	return ret ? ret : metadata & 1;
1645 }
1646 
1647 /**
1648  * usb4_port_retimer_nvm_sector_size() - Read retimer NVM sector size
1649  * @port: USB4 port
1650  * @index: Retimer index
1651  *
1652  * Reads NVM sector size (in bytes) of a retimer at @index. This
1653  * operation can be used to determine whether the retimer supports NVM
1654  * upgrade for example. Returns sector size in bytes or negative errno
1655  * in case of error. Specifically returns %-ENODEV if there is no
1656  * retimer at @index.
1657  */
1658 int usb4_port_retimer_nvm_sector_size(struct tb_port *port, u8 index)
1659 {
1660 	u32 metadata;
1661 	int ret;
1662 
1663 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_GET_NVM_SECTOR_SIZE,
1664 				   500);
1665 	if (ret)
1666 		return ret;
1667 
1668 	ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA, &metadata,
1669 				     sizeof(metadata));
1670 	return ret ? ret : metadata & USB4_NVM_SECTOR_SIZE_MASK;
1671 }
1672 
1673 /**
1674  * usb4_port_retimer_nvm_set_offset() - Set NVM write offset
1675  * @port: USB4 port
1676  * @index: Retimer index
1677  * @address: Start offset
1678  *
1679  * Exlicitly sets NVM write offset. Normally when writing to NVM this is
1680  * done automatically by usb4_port_retimer_nvm_write().
1681  *
1682  * Returns %0 in success and negative errno if there was a failure.
1683  */
1684 int usb4_port_retimer_nvm_set_offset(struct tb_port *port, u8 index,
1685 				     unsigned int address)
1686 {
1687 	u32 metadata, dwaddress;
1688 	int ret;
1689 
1690 	dwaddress = address / 4;
1691 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
1692 		  USB4_NVM_SET_OFFSET_MASK;
1693 
1694 	ret = usb4_port_retimer_write(port, index, USB4_SB_METADATA, &metadata,
1695 				      sizeof(metadata));
1696 	if (ret)
1697 		return ret;
1698 
1699 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_SET_OFFSET,
1700 				    500);
1701 }
1702 
1703 struct retimer_info {
1704 	struct tb_port *port;
1705 	u8 index;
1706 };
1707 
1708 static int usb4_port_retimer_nvm_write_next_block(void *data,
1709 	unsigned int dwaddress, const void *buf, size_t dwords)
1710 
1711 {
1712 	const struct retimer_info *info = data;
1713 	struct tb_port *port = info->port;
1714 	u8 index = info->index;
1715 	int ret;
1716 
1717 	ret = usb4_port_retimer_write(port, index, USB4_SB_DATA,
1718 				      buf, dwords * 4);
1719 	if (ret)
1720 		return ret;
1721 
1722 	return usb4_port_retimer_op(port, index,
1723 			USB4_SB_OPCODE_NVM_BLOCK_WRITE, 1000);
1724 }
1725 
1726 /**
1727  * usb4_port_retimer_nvm_write() - Write to retimer NVM
1728  * @port: USB4 port
1729  * @index: Retimer index
1730  * @address: Byte address where to start the write
1731  * @buf: Data to write
1732  * @size: Size in bytes how much to write
1733  *
1734  * Writes @size bytes from @buf to the retimer NVM. Used for NVM
1735  * upgrade. Returns %0 if the data was written successfully and negative
1736  * errno in case of failure. Specifically returns %-ENODEV if there is
1737  * no retimer at @index.
1738  */
1739 int usb4_port_retimer_nvm_write(struct tb_port *port, u8 index, unsigned int address,
1740 				const void *buf, size_t size)
1741 {
1742 	struct retimer_info info = { .port = port, .index = index };
1743 	int ret;
1744 
1745 	ret = usb4_port_retimer_nvm_set_offset(port, index, address);
1746 	if (ret)
1747 		return ret;
1748 
1749 	return tb_nvm_write_data(address, buf, size, USB4_DATA_RETRIES,
1750 				 usb4_port_retimer_nvm_write_next_block, &info);
1751 }
1752 
1753 /**
1754  * usb4_port_retimer_nvm_authenticate() - Start retimer NVM upgrade
1755  * @port: USB4 port
1756  * @index: Retimer index
1757  *
1758  * After the new NVM image has been written via usb4_port_retimer_nvm_write()
1759  * this function can be used to trigger the NVM upgrade process. If
1760  * successful the retimer restarts with the new NVM and may not have the
1761  * index set so one needs to call usb4_port_enumerate_retimers() to
1762  * force index to be assigned.
1763  */
1764 int usb4_port_retimer_nvm_authenticate(struct tb_port *port, u8 index)
1765 {
1766 	u32 val;
1767 
1768 	/*
1769 	 * We need to use the raw operation here because once the
1770 	 * authentication completes the retimer index is not set anymore
1771 	 * so we do not get back the status now.
1772 	 */
1773 	val = USB4_SB_OPCODE_NVM_AUTH_WRITE;
1774 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
1775 				  USB4_SB_OPCODE, &val, sizeof(val));
1776 }
1777 
1778 /**
1779  * usb4_port_retimer_nvm_authenticate_status() - Read status of NVM upgrade
1780  * @port: USB4 port
1781  * @index: Retimer index
1782  * @status: Raw status code read from metadata
1783  *
1784  * This can be called after usb4_port_retimer_nvm_authenticate() and
1785  * usb4_port_enumerate_retimers() to fetch status of the NVM upgrade.
1786  *
1787  * Returns %0 if the authentication status was successfully read. The
1788  * completion metadata (the result) is then stored into @status. If
1789  * reading the status fails, returns negative errno.
1790  */
1791 int usb4_port_retimer_nvm_authenticate_status(struct tb_port *port, u8 index,
1792 					      u32 *status)
1793 {
1794 	u32 metadata, val;
1795 	int ret;
1796 
1797 	ret = usb4_port_retimer_read(port, index, USB4_SB_OPCODE, &val,
1798 				     sizeof(val));
1799 	if (ret)
1800 		return ret;
1801 
1802 	switch (val) {
1803 	case 0:
1804 		*status = 0;
1805 		return 0;
1806 
1807 	case USB4_SB_OPCODE_ERR:
1808 		ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA,
1809 					     &metadata, sizeof(metadata));
1810 		if (ret)
1811 			return ret;
1812 
1813 		*status = metadata & USB4_SB_METADATA_NVM_AUTH_WRITE_MASK;
1814 		return 0;
1815 
1816 	case USB4_SB_OPCODE_ONS:
1817 		return -EOPNOTSUPP;
1818 
1819 	default:
1820 		return -EIO;
1821 	}
1822 }
1823 
1824 static int usb4_port_retimer_nvm_read_block(void *data, unsigned int dwaddress,
1825 					    void *buf, size_t dwords)
1826 {
1827 	const struct retimer_info *info = data;
1828 	struct tb_port *port = info->port;
1829 	u8 index = info->index;
1830 	u32 metadata;
1831 	int ret;
1832 
1833 	metadata = dwaddress << USB4_NVM_READ_OFFSET_SHIFT;
1834 	if (dwords < NVM_DATA_DWORDS)
1835 		metadata |= dwords << USB4_NVM_READ_LENGTH_SHIFT;
1836 
1837 	ret = usb4_port_retimer_write(port, index, USB4_SB_METADATA, &metadata,
1838 				      sizeof(metadata));
1839 	if (ret)
1840 		return ret;
1841 
1842 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_READ, 500);
1843 	if (ret)
1844 		return ret;
1845 
1846 	return usb4_port_retimer_read(port, index, USB4_SB_DATA, buf,
1847 				      dwords * 4);
1848 }
1849 
1850 /**
1851  * usb4_port_retimer_nvm_read() - Read contents of retimer NVM
1852  * @port: USB4 port
1853  * @index: Retimer index
1854  * @address: NVM address (in bytes) to start reading
1855  * @buf: Data read from NVM is stored here
1856  * @size: Number of bytes to read
1857  *
1858  * Reads retimer NVM and copies the contents to @buf. Returns %0 if the
1859  * read was successful and negative errno in case of failure.
1860  * Specifically returns %-ENODEV if there is no retimer at @index.
1861  */
1862 int usb4_port_retimer_nvm_read(struct tb_port *port, u8 index,
1863 			       unsigned int address, void *buf, size_t size)
1864 {
1865 	struct retimer_info info = { .port = port, .index = index };
1866 
1867 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
1868 				usb4_port_retimer_nvm_read_block, &info);
1869 }
1870 
1871 /**
1872  * usb4_usb3_port_max_link_rate() - Maximum support USB3 link rate
1873  * @port: USB3 adapter port
1874  *
1875  * Return maximum supported link rate of a USB3 adapter in Mb/s.
1876  * Negative errno in case of error.
1877  */
1878 int usb4_usb3_port_max_link_rate(struct tb_port *port)
1879 {
1880 	int ret, lr;
1881 	u32 val;
1882 
1883 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
1884 		return -EINVAL;
1885 
1886 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1887 			   port->cap_adap + ADP_USB3_CS_4, 1);
1888 	if (ret)
1889 		return ret;
1890 
1891 	lr = (val & ADP_USB3_CS_4_MSLR_MASK) >> ADP_USB3_CS_4_MSLR_SHIFT;
1892 	return lr == ADP_USB3_CS_4_MSLR_20G ? 20000 : 10000;
1893 }
1894 
1895 /**
1896  * usb4_usb3_port_actual_link_rate() - Established USB3 link rate
1897  * @port: USB3 adapter port
1898  *
1899  * Return actual established link rate of a USB3 adapter in Mb/s. If the
1900  * link is not up returns %0 and negative errno in case of failure.
1901  */
1902 int usb4_usb3_port_actual_link_rate(struct tb_port *port)
1903 {
1904 	int ret, lr;
1905 	u32 val;
1906 
1907 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
1908 		return -EINVAL;
1909 
1910 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1911 			   port->cap_adap + ADP_USB3_CS_4, 1);
1912 	if (ret)
1913 		return ret;
1914 
1915 	if (!(val & ADP_USB3_CS_4_ULV))
1916 		return 0;
1917 
1918 	lr = val & ADP_USB3_CS_4_ALR_MASK;
1919 	return lr == ADP_USB3_CS_4_ALR_20G ? 20000 : 10000;
1920 }
1921 
1922 static int usb4_usb3_port_cm_request(struct tb_port *port, bool request)
1923 {
1924 	int ret;
1925 	u32 val;
1926 
1927 	if (!tb_port_is_usb3_down(port))
1928 		return -EINVAL;
1929 	if (tb_route(port->sw))
1930 		return -EINVAL;
1931 
1932 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1933 			   port->cap_adap + ADP_USB3_CS_2, 1);
1934 	if (ret)
1935 		return ret;
1936 
1937 	if (request)
1938 		val |= ADP_USB3_CS_2_CMR;
1939 	else
1940 		val &= ~ADP_USB3_CS_2_CMR;
1941 
1942 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1943 			    port->cap_adap + ADP_USB3_CS_2, 1);
1944 	if (ret)
1945 		return ret;
1946 
1947 	/*
1948 	 * We can use val here directly as the CMR bit is in the same place
1949 	 * as HCA. Just mask out others.
1950 	 */
1951 	val &= ADP_USB3_CS_2_CMR;
1952 	return usb4_port_wait_for_bit(port, port->cap_adap + ADP_USB3_CS_1,
1953 				      ADP_USB3_CS_1_HCA, val, 1500);
1954 }
1955 
1956 static inline int usb4_usb3_port_set_cm_request(struct tb_port *port)
1957 {
1958 	return usb4_usb3_port_cm_request(port, true);
1959 }
1960 
1961 static inline int usb4_usb3_port_clear_cm_request(struct tb_port *port)
1962 {
1963 	return usb4_usb3_port_cm_request(port, false);
1964 }
1965 
1966 static unsigned int usb3_bw_to_mbps(u32 bw, u8 scale)
1967 {
1968 	unsigned long uframes;
1969 
1970 	uframes = bw * 512UL << scale;
1971 	return DIV_ROUND_CLOSEST(uframes * 8000, 1000 * 1000);
1972 }
1973 
1974 static u32 mbps_to_usb3_bw(unsigned int mbps, u8 scale)
1975 {
1976 	unsigned long uframes;
1977 
1978 	/* 1 uframe is 1/8 ms (125 us) -> 1 / 8000 s */
1979 	uframes = ((unsigned long)mbps * 1000 *  1000) / 8000;
1980 	return DIV_ROUND_UP(uframes, 512UL << scale);
1981 }
1982 
1983 static int usb4_usb3_port_read_allocated_bandwidth(struct tb_port *port,
1984 						   int *upstream_bw,
1985 						   int *downstream_bw)
1986 {
1987 	u32 val, bw, scale;
1988 	int ret;
1989 
1990 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1991 			   port->cap_adap + ADP_USB3_CS_2, 1);
1992 	if (ret)
1993 		return ret;
1994 
1995 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
1996 			   port->cap_adap + ADP_USB3_CS_3, 1);
1997 	if (ret)
1998 		return ret;
1999 
2000 	scale &= ADP_USB3_CS_3_SCALE_MASK;
2001 
2002 	bw = val & ADP_USB3_CS_2_AUBW_MASK;
2003 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
2004 
2005 	bw = (val & ADP_USB3_CS_2_ADBW_MASK) >> ADP_USB3_CS_2_ADBW_SHIFT;
2006 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
2007 
2008 	return 0;
2009 }
2010 
2011 /**
2012  * usb4_usb3_port_allocated_bandwidth() - Bandwidth allocated for USB3
2013  * @port: USB3 adapter port
2014  * @upstream_bw: Allocated upstream bandwidth is stored here
2015  * @downstream_bw: Allocated downstream bandwidth is stored here
2016  *
2017  * Stores currently allocated USB3 bandwidth into @upstream_bw and
2018  * @downstream_bw in Mb/s. Returns %0 in case of success and negative
2019  * errno in failure.
2020  */
2021 int usb4_usb3_port_allocated_bandwidth(struct tb_port *port, int *upstream_bw,
2022 				       int *downstream_bw)
2023 {
2024 	int ret;
2025 
2026 	ret = usb4_usb3_port_set_cm_request(port);
2027 	if (ret)
2028 		return ret;
2029 
2030 	ret = usb4_usb3_port_read_allocated_bandwidth(port, upstream_bw,
2031 						      downstream_bw);
2032 	usb4_usb3_port_clear_cm_request(port);
2033 
2034 	return ret;
2035 }
2036 
2037 static int usb4_usb3_port_read_consumed_bandwidth(struct tb_port *port,
2038 						  int *upstream_bw,
2039 						  int *downstream_bw)
2040 {
2041 	u32 val, bw, scale;
2042 	int ret;
2043 
2044 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2045 			   port->cap_adap + ADP_USB3_CS_1, 1);
2046 	if (ret)
2047 		return ret;
2048 
2049 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
2050 			   port->cap_adap + ADP_USB3_CS_3, 1);
2051 	if (ret)
2052 		return ret;
2053 
2054 	scale &= ADP_USB3_CS_3_SCALE_MASK;
2055 
2056 	bw = val & ADP_USB3_CS_1_CUBW_MASK;
2057 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
2058 
2059 	bw = (val & ADP_USB3_CS_1_CDBW_MASK) >> ADP_USB3_CS_1_CDBW_SHIFT;
2060 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
2061 
2062 	return 0;
2063 }
2064 
2065 static int usb4_usb3_port_write_allocated_bandwidth(struct tb_port *port,
2066 						    int upstream_bw,
2067 						    int downstream_bw)
2068 {
2069 	u32 val, ubw, dbw, scale;
2070 	int ret;
2071 
2072 	/* Read the used scale, hardware default is 0 */
2073 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
2074 			   port->cap_adap + ADP_USB3_CS_3, 1);
2075 	if (ret)
2076 		return ret;
2077 
2078 	scale &= ADP_USB3_CS_3_SCALE_MASK;
2079 	ubw = mbps_to_usb3_bw(upstream_bw, scale);
2080 	dbw = mbps_to_usb3_bw(downstream_bw, scale);
2081 
2082 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2083 			   port->cap_adap + ADP_USB3_CS_2, 1);
2084 	if (ret)
2085 		return ret;
2086 
2087 	val &= ~(ADP_USB3_CS_2_AUBW_MASK | ADP_USB3_CS_2_ADBW_MASK);
2088 	val |= dbw << ADP_USB3_CS_2_ADBW_SHIFT;
2089 	val |= ubw;
2090 
2091 	return tb_port_write(port, &val, TB_CFG_PORT,
2092 			     port->cap_adap + ADP_USB3_CS_2, 1);
2093 }
2094 
2095 /**
2096  * usb4_usb3_port_allocate_bandwidth() - Allocate bandwidth for USB3
2097  * @port: USB3 adapter port
2098  * @upstream_bw: New upstream bandwidth
2099  * @downstream_bw: New downstream bandwidth
2100  *
2101  * This can be used to set how much bandwidth is allocated for the USB3
2102  * tunneled isochronous traffic. @upstream_bw and @downstream_bw are the
2103  * new values programmed to the USB3 adapter allocation registers. If
2104  * the values are lower than what is currently consumed the allocation
2105  * is set to what is currently consumed instead (consumed bandwidth
2106  * cannot be taken away by CM). The actual new values are returned in
2107  * @upstream_bw and @downstream_bw.
2108  *
2109  * Returns %0 in case of success and negative errno if there was a
2110  * failure.
2111  */
2112 int usb4_usb3_port_allocate_bandwidth(struct tb_port *port, int *upstream_bw,
2113 				      int *downstream_bw)
2114 {
2115 	int ret, consumed_up, consumed_down, allocate_up, allocate_down;
2116 
2117 	ret = usb4_usb3_port_set_cm_request(port);
2118 	if (ret)
2119 		return ret;
2120 
2121 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
2122 						     &consumed_down);
2123 	if (ret)
2124 		goto err_request;
2125 
2126 	/* Don't allow it go lower than what is consumed */
2127 	allocate_up = max(*upstream_bw, consumed_up);
2128 	allocate_down = max(*downstream_bw, consumed_down);
2129 
2130 	ret = usb4_usb3_port_write_allocated_bandwidth(port, allocate_up,
2131 						       allocate_down);
2132 	if (ret)
2133 		goto err_request;
2134 
2135 	*upstream_bw = allocate_up;
2136 	*downstream_bw = allocate_down;
2137 
2138 err_request:
2139 	usb4_usb3_port_clear_cm_request(port);
2140 	return ret;
2141 }
2142 
2143 /**
2144  * usb4_usb3_port_release_bandwidth() - Release allocated USB3 bandwidth
2145  * @port: USB3 adapter port
2146  * @upstream_bw: New allocated upstream bandwidth
2147  * @downstream_bw: New allocated downstream bandwidth
2148  *
2149  * Releases USB3 allocated bandwidth down to what is actually consumed.
2150  * The new bandwidth is returned in @upstream_bw and @downstream_bw.
2151  *
2152  * Returns 0% in success and negative errno in case of failure.
2153  */
2154 int usb4_usb3_port_release_bandwidth(struct tb_port *port, int *upstream_bw,
2155 				     int *downstream_bw)
2156 {
2157 	int ret, consumed_up, consumed_down;
2158 
2159 	ret = usb4_usb3_port_set_cm_request(port);
2160 	if (ret)
2161 		return ret;
2162 
2163 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
2164 						     &consumed_down);
2165 	if (ret)
2166 		goto err_request;
2167 
2168 	/*
2169 	 * Always keep 1000 Mb/s to make sure xHCI has at least some
2170 	 * bandwidth available for isochronous traffic.
2171 	 */
2172 	if (consumed_up < 1000)
2173 		consumed_up = 1000;
2174 	if (consumed_down < 1000)
2175 		consumed_down = 1000;
2176 
2177 	ret = usb4_usb3_port_write_allocated_bandwidth(port, consumed_up,
2178 						       consumed_down);
2179 	if (ret)
2180 		goto err_request;
2181 
2182 	*upstream_bw = consumed_up;
2183 	*downstream_bw = consumed_down;
2184 
2185 err_request:
2186 	usb4_usb3_port_clear_cm_request(port);
2187 	return ret;
2188 }
2189 
2190 static bool is_usb4_dpin(const struct tb_port *port)
2191 {
2192 	if (!tb_port_is_dpin(port))
2193 		return false;
2194 	if (!tb_switch_is_usb4(port->sw))
2195 		return false;
2196 	return true;
2197 }
2198 
2199 /**
2200  * usb4_dp_port_set_cm_id() - Assign CM ID to the DP IN adapter
2201  * @port: DP IN adapter
2202  * @cm_id: CM ID to assign
2203  *
2204  * Sets CM ID for the @port. Returns %0 on success and negative errno
2205  * otherwise. Speficially returns %-EOPNOTSUPP if the @port does not
2206  * support this.
2207  */
2208 int usb4_dp_port_set_cm_id(struct tb_port *port, int cm_id)
2209 {
2210 	u32 val;
2211 	int ret;
2212 
2213 	if (!is_usb4_dpin(port))
2214 		return -EOPNOTSUPP;
2215 
2216 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2217 			   port->cap_adap + ADP_DP_CS_2, 1);
2218 	if (ret)
2219 		return ret;
2220 
2221 	val &= ~ADP_DP_CS_2_CM_ID_MASK;
2222 	val |= cm_id << ADP_DP_CS_2_CM_ID_SHIFT;
2223 
2224 	return tb_port_write(port, &val, TB_CFG_PORT,
2225 			     port->cap_adap + ADP_DP_CS_2, 1);
2226 }
2227 
2228 /**
2229  * usb4_dp_port_bw_mode_supported() - Is the bandwidth allocation mode supported
2230  * @port: DP IN adapter to check
2231  *
2232  * Can be called to any DP IN adapter. Returns true if the adapter
2233  * supports USB4 bandwidth allocation mode, false otherwise.
2234  */
2235 bool usb4_dp_port_bw_mode_supported(struct tb_port *port)
2236 {
2237 	int ret;
2238 	u32 val;
2239 
2240 	if (!is_usb4_dpin(port))
2241 		return false;
2242 
2243 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2244 			   port->cap_adap + DP_LOCAL_CAP, 1);
2245 	if (ret)
2246 		return false;
2247 
2248 	return !!(val & DP_COMMON_CAP_BW_MODE);
2249 }
2250 
2251 /**
2252  * usb4_dp_port_bw_mode_enabled() - Is the bandwidth allocation mode enabled
2253  * @port: DP IN adapter to check
2254  *
2255  * Can be called to any DP IN adapter. Returns true if the bandwidth
2256  * allocation mode has been enabled, false otherwise.
2257  */
2258 bool usb4_dp_port_bw_mode_enabled(struct tb_port *port)
2259 {
2260 	int ret;
2261 	u32 val;
2262 
2263 	if (!is_usb4_dpin(port))
2264 		return false;
2265 
2266 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2267 			   port->cap_adap + ADP_DP_CS_8, 1);
2268 	if (ret)
2269 		return false;
2270 
2271 	return !!(val & ADP_DP_CS_8_DPME);
2272 }
2273 
2274 /**
2275  * usb4_dp_port_set_cm_bw_mode_supported() - Set/clear CM support for bandwidth allocation mode
2276  * @port: DP IN adapter
2277  * @supported: Does the CM support bandwidth allocation mode
2278  *
2279  * Can be called to any DP IN adapter. Sets or clears the CM support bit
2280  * of the DP IN adapter. Returns %0 in success and negative errno
2281  * otherwise. Specifically returns %-OPNOTSUPP if the passed in adapter
2282  * does not support this.
2283  */
2284 int usb4_dp_port_set_cm_bw_mode_supported(struct tb_port *port, bool supported)
2285 {
2286 	u32 val;
2287 	int ret;
2288 
2289 	if (!is_usb4_dpin(port))
2290 		return -EOPNOTSUPP;
2291 
2292 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2293 			   port->cap_adap + ADP_DP_CS_2, 1);
2294 	if (ret)
2295 		return ret;
2296 
2297 	if (supported)
2298 		val |= ADP_DP_CS_2_CMMS;
2299 	else
2300 		val &= ~ADP_DP_CS_2_CMMS;
2301 
2302 	return tb_port_write(port, &val, TB_CFG_PORT,
2303 			     port->cap_adap + ADP_DP_CS_2, 1);
2304 }
2305 
2306 /**
2307  * usb4_dp_port_group_id() - Return Group ID assigned for the adapter
2308  * @port: DP IN adapter
2309  *
2310  * Reads bandwidth allocation Group ID from the DP IN adapter and
2311  * returns it. If the adapter does not support setting Group_ID
2312  * %-EOPNOTSUPP is returned.
2313  */
2314 int usb4_dp_port_group_id(struct tb_port *port)
2315 {
2316 	u32 val;
2317 	int ret;
2318 
2319 	if (!is_usb4_dpin(port))
2320 		return -EOPNOTSUPP;
2321 
2322 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2323 			   port->cap_adap + ADP_DP_CS_2, 1);
2324 	if (ret)
2325 		return ret;
2326 
2327 	return (val & ADP_DP_CS_2_GROUP_ID_MASK) >> ADP_DP_CS_2_GROUP_ID_SHIFT;
2328 }
2329 
2330 /**
2331  * usb4_dp_port_set_group_id() - Set adapter Group ID
2332  * @port: DP IN adapter
2333  * @group_id: Group ID for the adapter
2334  *
2335  * Sets bandwidth allocation mode Group ID for the DP IN adapter.
2336  * Returns %0 in case of success and negative errno otherwise.
2337  * Specifically returns %-EOPNOTSUPP if the adapter does not support
2338  * this.
2339  */
2340 int usb4_dp_port_set_group_id(struct tb_port *port, int group_id)
2341 {
2342 	u32 val;
2343 	int ret;
2344 
2345 	if (!is_usb4_dpin(port))
2346 		return -EOPNOTSUPP;
2347 
2348 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2349 			   port->cap_adap + ADP_DP_CS_2, 1);
2350 	if (ret)
2351 		return ret;
2352 
2353 	val &= ~ADP_DP_CS_2_GROUP_ID_MASK;
2354 	val |= group_id << ADP_DP_CS_2_GROUP_ID_SHIFT;
2355 
2356 	return tb_port_write(port, &val, TB_CFG_PORT,
2357 			     port->cap_adap + ADP_DP_CS_2, 1);
2358 }
2359 
2360 /**
2361  * usb4_dp_port_nrd() - Read non-reduced rate and lanes
2362  * @port: DP IN adapter
2363  * @rate: Non-reduced rate in Mb/s is placed here
2364  * @lanes: Non-reduced lanes are placed here
2365  *
2366  * Reads the non-reduced rate and lanes from the DP IN adapter. Returns
2367  * %0 in success and negative errno otherwise. Specifically returns
2368  * %-EOPNOTSUPP if the adapter does not support this.
2369  */
2370 int usb4_dp_port_nrd(struct tb_port *port, int *rate, int *lanes)
2371 {
2372 	u32 val, tmp;
2373 	int ret;
2374 
2375 	if (!is_usb4_dpin(port))
2376 		return -EOPNOTSUPP;
2377 
2378 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2379 			   port->cap_adap + ADP_DP_CS_2, 1);
2380 	if (ret)
2381 		return ret;
2382 
2383 	tmp = (val & ADP_DP_CS_2_NRD_MLR_MASK) >> ADP_DP_CS_2_NRD_MLR_SHIFT;
2384 	switch (tmp) {
2385 	case DP_COMMON_CAP_RATE_RBR:
2386 		*rate = 1620;
2387 		break;
2388 	case DP_COMMON_CAP_RATE_HBR:
2389 		*rate = 2700;
2390 		break;
2391 	case DP_COMMON_CAP_RATE_HBR2:
2392 		*rate = 5400;
2393 		break;
2394 	case DP_COMMON_CAP_RATE_HBR3:
2395 		*rate = 8100;
2396 		break;
2397 	}
2398 
2399 	tmp = val & ADP_DP_CS_2_NRD_MLC_MASK;
2400 	switch (tmp) {
2401 	case DP_COMMON_CAP_1_LANE:
2402 		*lanes = 1;
2403 		break;
2404 	case DP_COMMON_CAP_2_LANES:
2405 		*lanes = 2;
2406 		break;
2407 	case DP_COMMON_CAP_4_LANES:
2408 		*lanes = 4;
2409 		break;
2410 	}
2411 
2412 	return 0;
2413 }
2414 
2415 /**
2416  * usb4_dp_port_set_nrd() - Set non-reduced rate and lanes
2417  * @port: DP IN adapter
2418  * @rate: Non-reduced rate in Mb/s
2419  * @lanes: Non-reduced lanes
2420  *
2421  * Before the capabilities reduction this function can be used to set
2422  * the non-reduced values for the DP IN adapter. Returns %0 in success
2423  * and negative errno otherwise. If the adapter does not support this
2424  * %-EOPNOTSUPP is returned.
2425  */
2426 int usb4_dp_port_set_nrd(struct tb_port *port, int rate, int lanes)
2427 {
2428 	u32 val;
2429 	int ret;
2430 
2431 	if (!is_usb4_dpin(port))
2432 		return -EOPNOTSUPP;
2433 
2434 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2435 			   port->cap_adap + ADP_DP_CS_2, 1);
2436 	if (ret)
2437 		return ret;
2438 
2439 	val &= ~ADP_DP_CS_2_NRD_MLR_MASK;
2440 
2441 	switch (rate) {
2442 	case 1620:
2443 		break;
2444 	case 2700:
2445 		val |= (DP_COMMON_CAP_RATE_HBR << ADP_DP_CS_2_NRD_MLR_SHIFT)
2446 			& ADP_DP_CS_2_NRD_MLR_MASK;
2447 		break;
2448 	case 5400:
2449 		val |= (DP_COMMON_CAP_RATE_HBR2 << ADP_DP_CS_2_NRD_MLR_SHIFT)
2450 			& ADP_DP_CS_2_NRD_MLR_MASK;
2451 		break;
2452 	case 8100:
2453 		val |= (DP_COMMON_CAP_RATE_HBR3 << ADP_DP_CS_2_NRD_MLR_SHIFT)
2454 			& ADP_DP_CS_2_NRD_MLR_MASK;
2455 		break;
2456 	default:
2457 		return -EINVAL;
2458 	}
2459 
2460 	val &= ~ADP_DP_CS_2_NRD_MLC_MASK;
2461 
2462 	switch (lanes) {
2463 	case 1:
2464 		break;
2465 	case 2:
2466 		val |= DP_COMMON_CAP_2_LANES;
2467 		break;
2468 	case 4:
2469 		val |= DP_COMMON_CAP_4_LANES;
2470 		break;
2471 	default:
2472 		return -EINVAL;
2473 	}
2474 
2475 	return tb_port_write(port, &val, TB_CFG_PORT,
2476 			     port->cap_adap + ADP_DP_CS_2, 1);
2477 }
2478 
2479 /**
2480  * usb4_dp_port_granularity() - Return granularity for the bandwidth values
2481  * @port: DP IN adapter
2482  *
2483  * Reads the programmed granularity from @port. If the DP IN adapter does
2484  * not support bandwidth allocation mode returns %-EOPNOTSUPP and negative
2485  * errno in other error cases.
2486  */
2487 int usb4_dp_port_granularity(struct tb_port *port)
2488 {
2489 	u32 val;
2490 	int ret;
2491 
2492 	if (!is_usb4_dpin(port))
2493 		return -EOPNOTSUPP;
2494 
2495 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2496 			   port->cap_adap + ADP_DP_CS_2, 1);
2497 	if (ret)
2498 		return ret;
2499 
2500 	val &= ADP_DP_CS_2_GR_MASK;
2501 	val >>= ADP_DP_CS_2_GR_SHIFT;
2502 
2503 	switch (val) {
2504 	case ADP_DP_CS_2_GR_0_25G:
2505 		return 250;
2506 	case ADP_DP_CS_2_GR_0_5G:
2507 		return 500;
2508 	case ADP_DP_CS_2_GR_1G:
2509 		return 1000;
2510 	}
2511 
2512 	return -EINVAL;
2513 }
2514 
2515 /**
2516  * usb4_dp_port_set_granularity() - Set granularity for the bandwidth values
2517  * @port: DP IN adapter
2518  * @granularity: Granularity in Mb/s. Supported values: 1000, 500 and 250.
2519  *
2520  * Sets the granularity used with the estimated, allocated and requested
2521  * bandwidth. Returns %0 in success and negative errno otherwise. If the
2522  * adapter does not support this %-EOPNOTSUPP is returned.
2523  */
2524 int usb4_dp_port_set_granularity(struct tb_port *port, int granularity)
2525 {
2526 	u32 val;
2527 	int ret;
2528 
2529 	if (!is_usb4_dpin(port))
2530 		return -EOPNOTSUPP;
2531 
2532 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2533 			   port->cap_adap + ADP_DP_CS_2, 1);
2534 	if (ret)
2535 		return ret;
2536 
2537 	val &= ~ADP_DP_CS_2_GR_MASK;
2538 
2539 	switch (granularity) {
2540 	case 250:
2541 		val |= ADP_DP_CS_2_GR_0_25G << ADP_DP_CS_2_GR_SHIFT;
2542 		break;
2543 	case 500:
2544 		val |= ADP_DP_CS_2_GR_0_5G << ADP_DP_CS_2_GR_SHIFT;
2545 		break;
2546 	case 1000:
2547 		val |= ADP_DP_CS_2_GR_1G << ADP_DP_CS_2_GR_SHIFT;
2548 		break;
2549 	default:
2550 		return -EINVAL;
2551 	}
2552 
2553 	return tb_port_write(port, &val, TB_CFG_PORT,
2554 			     port->cap_adap + ADP_DP_CS_2, 1);
2555 }
2556 
2557 /**
2558  * usb4_dp_port_set_estimated_bw() - Set estimated bandwidth
2559  * @port: DP IN adapter
2560  * @bw: Estimated bandwidth in Mb/s.
2561  *
2562  * Sets the estimated bandwidth to @bw. Set the granularity by calling
2563  * usb4_dp_port_set_granularity() before calling this. The @bw is round
2564  * down to the closest granularity multiplier. Returns %0 in success
2565  * and negative errno otherwise. Specifically returns %-EOPNOTSUPP if
2566  * the adapter does not support this.
2567  */
2568 int usb4_dp_port_set_estimated_bw(struct tb_port *port, int bw)
2569 {
2570 	u32 val, granularity;
2571 	int ret;
2572 
2573 	if (!is_usb4_dpin(port))
2574 		return -EOPNOTSUPP;
2575 
2576 	ret = usb4_dp_port_granularity(port);
2577 	if (ret < 0)
2578 		return ret;
2579 	granularity = ret;
2580 
2581 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2582 			   port->cap_adap + ADP_DP_CS_2, 1);
2583 	if (ret)
2584 		return ret;
2585 
2586 	val &= ~ADP_DP_CS_2_ESTIMATED_BW_MASK;
2587 	val |= (bw / granularity) << ADP_DP_CS_2_ESTIMATED_BW_SHIFT;
2588 
2589 	return tb_port_write(port, &val, TB_CFG_PORT,
2590 			     port->cap_adap + ADP_DP_CS_2, 1);
2591 }
2592 
2593 /**
2594  * usb4_dp_port_allocated_bw() - Return allocated bandwidth
2595  * @port: DP IN adapter
2596  *
2597  * Reads and returns allocated bandwidth for @port in Mb/s (taking into
2598  * account the programmed granularity). Returns negative errno in case
2599  * of error.
2600  */
2601 int usb4_dp_port_allocated_bw(struct tb_port *port)
2602 {
2603 	u32 val, granularity;
2604 	int ret;
2605 
2606 	if (!is_usb4_dpin(port))
2607 		return -EOPNOTSUPP;
2608 
2609 	ret = usb4_dp_port_granularity(port);
2610 	if (ret < 0)
2611 		return ret;
2612 	granularity = ret;
2613 
2614 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2615 			   port->cap_adap + DP_STATUS, 1);
2616 	if (ret)
2617 		return ret;
2618 
2619 	val &= DP_STATUS_ALLOCATED_BW_MASK;
2620 	val >>= DP_STATUS_ALLOCATED_BW_SHIFT;
2621 
2622 	return val * granularity;
2623 }
2624 
2625 static int __usb4_dp_port_set_cm_ack(struct tb_port *port, bool ack)
2626 {
2627 	u32 val;
2628 	int ret;
2629 
2630 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2631 			   port->cap_adap + ADP_DP_CS_2, 1);
2632 	if (ret)
2633 		return ret;
2634 
2635 	if (ack)
2636 		val |= ADP_DP_CS_2_CA;
2637 	else
2638 		val &= ~ADP_DP_CS_2_CA;
2639 
2640 	return tb_port_write(port, &val, TB_CFG_PORT,
2641 			     port->cap_adap + ADP_DP_CS_2, 1);
2642 }
2643 
2644 static inline int usb4_dp_port_set_cm_ack(struct tb_port *port)
2645 {
2646 	return __usb4_dp_port_set_cm_ack(port, true);
2647 }
2648 
2649 static int usb4_dp_port_wait_and_clear_cm_ack(struct tb_port *port,
2650 					      int timeout_msec)
2651 {
2652 	ktime_t end;
2653 	u32 val;
2654 	int ret;
2655 
2656 	ret = __usb4_dp_port_set_cm_ack(port, false);
2657 	if (ret)
2658 		return ret;
2659 
2660 	end = ktime_add_ms(ktime_get(), timeout_msec);
2661 	do {
2662 		ret = tb_port_read(port, &val, TB_CFG_PORT,
2663 				   port->cap_adap + ADP_DP_CS_8, 1);
2664 		if (ret)
2665 			return ret;
2666 
2667 		if (!(val & ADP_DP_CS_8_DR))
2668 			break;
2669 
2670 		usleep_range(50, 100);
2671 	} while (ktime_before(ktime_get(), end));
2672 
2673 	if (val & ADP_DP_CS_8_DR)
2674 		return -ETIMEDOUT;
2675 
2676 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2677 			   port->cap_adap + ADP_DP_CS_2, 1);
2678 	if (ret)
2679 		return ret;
2680 
2681 	val &= ~ADP_DP_CS_2_CA;
2682 	return tb_port_write(port, &val, TB_CFG_PORT,
2683 			     port->cap_adap + ADP_DP_CS_2, 1);
2684 }
2685 
2686 /**
2687  * usb4_dp_port_allocate_bw() - Set allocated bandwidth
2688  * @port: DP IN adapter
2689  * @bw: New allocated bandwidth in Mb/s
2690  *
2691  * Communicates the new allocated bandwidth with the DPCD (graphics
2692  * driver). Takes into account the programmed granularity. Returns %0 in
2693  * success and negative errno in case of error.
2694  */
2695 int usb4_dp_port_allocate_bw(struct tb_port *port, int bw)
2696 {
2697 	u32 val, granularity;
2698 	int ret;
2699 
2700 	if (!is_usb4_dpin(port))
2701 		return -EOPNOTSUPP;
2702 
2703 	ret = usb4_dp_port_granularity(port);
2704 	if (ret < 0)
2705 		return ret;
2706 	granularity = ret;
2707 
2708 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2709 			   port->cap_adap + DP_STATUS, 1);
2710 	if (ret)
2711 		return ret;
2712 
2713 	val &= ~DP_STATUS_ALLOCATED_BW_MASK;
2714 	val |= (bw / granularity) << DP_STATUS_ALLOCATED_BW_SHIFT;
2715 
2716 	ret = tb_port_write(port, &val, TB_CFG_PORT,
2717 			    port->cap_adap + DP_STATUS, 1);
2718 	if (ret)
2719 		return ret;
2720 
2721 	ret = usb4_dp_port_set_cm_ack(port);
2722 	if (ret)
2723 		return ret;
2724 
2725 	return usb4_dp_port_wait_and_clear_cm_ack(port, 500);
2726 }
2727 
2728 /**
2729  * usb4_dp_port_requested_bw() - Read requested bandwidth
2730  * @port: DP IN adapter
2731  *
2732  * Reads the DPCD (graphics driver) requested bandwidth and returns it
2733  * in Mb/s. Takes the programmed granularity into account. In case of
2734  * error returns negative errno. Specifically returns %-EOPNOTSUPP if
2735  * the adapter does not support bandwidth allocation mode, and %ENODATA
2736  * if there is no active bandwidth request from the graphics driver.
2737  */
2738 int usb4_dp_port_requested_bw(struct tb_port *port)
2739 {
2740 	u32 val, granularity;
2741 	int ret;
2742 
2743 	if (!is_usb4_dpin(port))
2744 		return -EOPNOTSUPP;
2745 
2746 	ret = usb4_dp_port_granularity(port);
2747 	if (ret < 0)
2748 		return ret;
2749 	granularity = ret;
2750 
2751 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2752 			   port->cap_adap + ADP_DP_CS_8, 1);
2753 	if (ret)
2754 		return ret;
2755 
2756 	if (!(val & ADP_DP_CS_8_DR))
2757 		return -ENODATA;
2758 
2759 	return (val & ADP_DP_CS_8_REQUESTED_BW_MASK) * granularity;
2760 }
2761